Azeotrope or azeotrope-like compositions of trifluoroiodomethane (CF3I) and hexafluoroacetone (HFA)

ABSTRACT

The present disclosure provides azeotrope or azeotrope-like compositions including trifluoroiodomethane (CF3I) and hexafluoroacetone (HFA), and a method of forming an azeotrope or azeotrope-like composition comprising the step of combining hexafluoroacetone (HFA) and trifluoroiodomethane (CF3I) to form an azeotrope or azeotrope-like comprising hexafluoroacetone (HFA) and trifluoroiodomethane (CF3I) having a boiling point of about −29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.62/745,664, filed Oct. 15, 2018, which is herein incorporated byreference in its entirety.

FIELD

The present disclosure is related to azeotrope or azeotrope-likecompositions and, in particular, to azeotrope or azeotrope-likecompositions comprising trifluoroiodomethane (CF₃I) andhexafluoroacetone (HFA).

BACKGROUND

Fluorocarbon based fluids have found widespread use in industry in anumber of applications, including as refrigerants, aerosol propellants,blowing agents, heat transfer media, gaseous dielectrics, and firesuppression.

However, certain compounds such as chlorofluorocarbons (CFCs) andhydrochlorofluorocarbons (HCFCs) are suspected of depleting atmosphericozone and, thus, are harmful to the environment. Moreover, some of thesecompounds are believed to contribute to global warming. Accordingly, itis desirable to use fluorocarbon fluids having low or even zero ozonedepletion potential, such as hydrofluorocarbons (HFCs), or those with aphotolyzable carbon iodine bond, which exhibit short atmosphericlifetime when released at ground level. The use of single componentfluids or azeotrope mixtures, which do not fractionate on boiling andevaporation, is also desirable.

Unfortunately, the identification of new, environmentally-safe,non-fractionating mixtures is complicated due to the fact that azeotropeformation is not readily predictable.

The industry is continually seeking new fluorocarbon-based mixtures thatoffer alternatives, and are considered environmentally safer substitutesfor CFCs, HCFCs and HFCs in use today. Of particular interest are iodidecontaining compounds and other fluorinated compounds, which have lowozone depletion potentials and low global warming potentials. Suchmixtures are the subject of this disclosure.

Although iodide containing compounds are of great potential interest,the purification of iodide containing compounds such astrifluoroiodomethane (CF₃I) has presented challenges, and techniques forthe removal of impurities from trifluoroiodomethane (CF₃I) such as, forexample, trifluoromethane (HFC-23), are in constant demand. Therefore,separation techniques such as azeotropic distillation, for example,would be highly desirable.

What is needed are compositions and techniques that may be used toprepare iodide containing compounds, such as trifluoroiodomethane(CF₃I), of high purity.

SUMMARY

The present disclosure provides azeotrope or azeotrope-like compositionscomprising trifluoroiodomethane (CF₃I) and hexafluoroacetone (HFA).

It is well-recognized in the art that it is not possible to predict theformation of azeotropes, and the present inventors have discoveredunexpectedly that trifluoroiodomethane (CF₃I) and hexafluoroacetone(HFA) form azeotrope or azeotrope-like compositions.

The present disclosure provides a composition comprising an azeotrope orazeotrope-like composition comprising, consisting essentially of, orconsisting of effective amounts of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I).

The azeotrope or azeotrope-like composition comprises, consistsessentially of, or consists of, from about 28 wt. % to about 75 wt. %hexafluoroacetone (HFA), from about 45 wt. % to about 70 wt. %hexafluoroacetone (HFA), from about 59 wt. % to about 60 wt. %hexafluoroacetone (HFA), or about 59.78 wt. % hexafluoroacetone (HFA),and from about 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I),from about 30 wt. % to about 55 wt. % trifluoroiodomethane (CF₃I), fromabout 40 wt. % to about 41 wt. % trifluoroiodomethane (CF₃I), or about40.22 wt. % trifluoroiodomethane (CF₃I).

In other words, the azeotrope or azeotrope-like composition may comprisefrom about 28 wt. % to about 75 wt. % hexafluoroacetone (HFA) and fromabout 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I), from about45 wt. % to about 70 wt. % hexafluoroacetone (HFA) and from about 30 wt.% to about 55 wt. % trifluoroiodomethane (CF₃I), from about 59 wt. % toabout 60 wt. % hexafluoroacetone (HFA) and from about 40 wt. % to about41 wt. % trifluoroiodomethane (CF₃I), or about 59.78 wt. %hexafluoroacetone (HFA) and about 40.22 wt. % trifluoroiodomethane(CF₃I). The azeotrope or azeotrope-like composition may consistessentially of hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I)in the above amounts, or consist of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) in the above amounts.

The azeotrope or azeotrope-like composition has a boiling point of about−29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

In another form thereof, the present disclosure provides an azeotrope orazeotrope-like composition consisting essentially of hexafluoroacetone(HFA) and trifluoroiodomethane (CF₃I) having a boiling point of about−29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

In a further form thereof, the present disclosure provides a method offorming an azeotrope or azeotrope-like composition comprising the stepof combining hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) toform an azeotrope or azeotrope-like composition comprising, consistingessentially of, or consisting of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I). The azeotrope or azeotrope-like compositionmay have a boiling point of about −29.84° C.±0.30° C. at a pressure ofabout 14.40 psia±0.30 psia.

In a still further form thereof, the present disclosure provides amethod of separating hexafluoroacetone (HFA) and trifluoroiodomethane(CF₃I) from a primary composition comprising hexafluoroacetone (HFA),trifluoroiodomethane (CF₃I) and at least one impurity, including thesteps of: forming, within the primary composition, a secondarycomposition which is an azeotrope or azeotrope-like compositioncomprising, consisting essentially of, or consisting of effectiveamounts of hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) wherethe azeotrope or azeotrope-like composition may have a boiling point ofabout −29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia;and separating the secondary composition from the primary compositionand the at least one impurity.

In the foregoing method, the forming step may comprise forming, withinthe primary composition, a secondary composition which is an azeotropeor azeotrope-like composition comprising, consisting essentially of, orconsisting of from about 10 wt. % to about 80 wt. % hexafluoroacetone(HFA) and from about 20 wt. % to about 90 wt. % trifluoroiodomethane(CF₃I) which may have a boiling point of about −29.84° C.±0.30° C. at apressure of about 14.40 psia±0.30 psia.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plot of temperature vs. weight percent hexafluoroacetone(HFA) measured according to Example 1.

DETAILED DESCRIPTION

It has been found that hexafluoroacetone (HFA) forms homogeneous,minimum boiling azeotrope and azeotrope-like compositions or mixtureswith trifluoroiodomethane (CF₃I), and the present disclosure provideshomogeneous azeotrope or azeotrope-like compositions comprisinghexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I). The azeotropeor azeotrope-like compositions may consist essentially ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I), or theazeotrope or azeotrope-like compositions may consist ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I).

The present inventors have found experimentally that hexafluoroacetone(HFA) and trifluoroiodomethane (CF₃I) form an azeotrope orazeotrope-like composition.

An “azeotrope” composition is a unique combination of two or morecomponents. An azeotrope composition can be characterized in variousways. For example, at a given pressure, an azeotrope composition boilsat a constant characteristic temperature which is either greater thanthe higher boiling point component (maximum boiling azeotrope) or lessthan the lower boiling point component (minimum boiling azeotrope). Atthis characteristic temperature the same composition will exist in boththe vapor and liquid phases. The azeotrope composition does notfractionate upon boiling or evaporation. Therefore, the components ofthe azeotrope composition cannot be separated during a phase change.

An azeotrope composition is also characterized in that at thecharacteristic azeotrope temperature, the bubble point pressure of theliquid phase is identical to the dew point pressure of the vapor phase.

The behavior of an azeotrope composition is in contrast with that of anon-azeotrope composition in which during boiling or evaporation, theliquid composition changes to a substantial degree.

For the purposes of the present disclosure, an azeotrope composition ischaracterized as that composition which boils at a constantcharacteristic temperature, the temperature being lower (a minimumboiling azeotrope) than the boiling points of the two or morecomponents, and thereby having the same composition in both the vaporand liquid phases.

One of ordinary skill in the art would understand however that atdifferent pressures, both the composition and the boiling point of theazeotrope composition will vary to some extent. Therefore, depending onthe temperature and/or pressure, an azeotrope composition can have avariable composition. The skilled person would therefore understand thatcomposition ranges, rather than fixed compositions, can be used todefine azeotrope compositions. In addition, an azeotrope may be definedin terms of exact weight percentages of each component of thecompositions characterized by a fixed boiling point at a specifiedpressure.

An “azeotrope-like” composition is a composition of two or morecomponents which behaves substantially as an azeotrope composition.Thus, for the purposes of this disclosure, an azeotrope-like compositionis a combination of two or more different components which, when inliquid form under given pressure, will boil at a substantially constanttemperature, and which will provide a vapor composition substantiallyidentical to the liquid composition undergoing boiling.

For the purposes of this disclosure, an azeotrope-like composition is acomposition or range of compositions which boils at a temperature rangeof about −29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30psia.

Azeotrope or azeotrope-like compositions can be identified using anumber of different methods.

For the purposes of this disclosure the azeotrope or azeotrope-likecomposition is identified experimentally using an ebulliometer (Walas,Phase Equilibria in Chemical Engineering, Butterworth-Heinemann, 1985,533-544). An ebulliometer is designed to provide extremely accuratemeasurements of the boiling points of liquids by measuring thetemperature of the vapor-liquid equilibrium.

The boiling points of each of the components alone are measured at aconstant pressure. As the skilled person will appreciate, for a binaryazeotrope or azeotrope-like composition, the boiling point of one of thecomponents of the composition is initially measured. The secondcomponent of the composition is then added in varying amounts and theboiling point of each of the obtained compositions is measured using theebulliometer at said constant pressure.

The measured boiling points are plotted against the composition of thetested composition, for example, for a binary azeotrope, the amount ofthe second component added to the composition, (expressed as eitherweight % or mole %). The presence of an azeotrope composition can beidentified by the observation of a maximum or minimum boilingtemperature which is greater or less than the boiling points of any ofthe components alone.

As the skilled person will appreciate, the identification of theazeotrope or azeotrope-like composition is made by the comparison of thechange in the boiling point of the composition on addition of the secondcomponent to the first component, relative to the boiling point of thefirst component. Thus, it is not necessary that the system be calibratedto the reported boiling point of the particular components in order tomeasure the change in boiling point.

As previously discussed, at the maximum or minimum boiling point, thecomposition of the vapor phase will be identical to the composition ofthe liquid phase. The azeotrope-like composition is therefore thatcomposition of components which provides a substantially constantminimum or maximum boiling point, that is a boiling point of about−29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia, atwhich substantially constant boiling point the composition of the vaporphase will be substantially identical to the composition of the liquidphase.

The present disclosure provides an azeotrope or azeotrope-likecomposition which comprises effective amounts of hexafluoroacetone (HFA)and trifluoroiodomethane (CF₃I) to form an azeotrope or azeotrope-likecomposition. As used herein, the term “effective amount” is an amount ofeach component which, when combined with the other component, results inthe formation of an azeotrope or azeotrope-like mixture.

The present azeotrope or azeotrope-like compositions may consistessentially of combinations of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I), or consist of combinations ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I).

As used herein, the term “consisting essentially of”, with respect tothe components of an azeotrope or azeotrope-like composition or mixture,means the composition contains the indicated components in an azeotropeor azeotrope-like ratio, and may contain additional components providedthat the additional components do not form new azeotrope orazeotrope-like systems. For example, azeotrope-like mixtures consistingessentially of two compounds are those that form binary azeotropes,which optionally may include one or more additional components, providedthat the additional components do not render the mixture non-azeotropicand do not form an azeotrope with either or both of the compounds (e.g.,do not form a ternary or higher azeotrope).

The present disclosure also provides a method of forming an azeotrope orazeotrope-like composition by mixing, combining, or blending, effectiveamounts of, hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I). Anyof a wide variety of methods known in the art for combining two or morecomponents to form a composition can be used in the present methods. Forexample, hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) can bemixed, blended, or otherwise combined by hand and/or by machine, as partof a batch or continuous reaction and/or process, or via combinations oftwo or more such steps. Both hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) are commercially available and can beprocured from several different vendors. The components can be providedin the required amounts, for example by weighing and then combining theamounts.

The azeotrope or azeotrope-like composition comprises, consistsessentially of, or consists of, from about 28 wt. % to about 75 wt. %hexafluoroacetone (HFA), from about 45 wt. % to about 70 wt. %hexafluoroacetone (HFA), from about 59 wt. % to about 60 wt. %hexafluoroacetone (HFA), or about 59.78 wt. % hexafluoroacetone (HFA),and from about 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I),from about 30 wt. % to about 55 wt. % trifluoroiodomethane (CF₃I), fromabout 40 wt. % to about 41 wt. % trifluoroiodomethane (CF₃I), or about40.22 wt. % trifluoroiodomethane (CF₃I).

In other words, the azeotrope or azeotrope-like composition may comprisefrom about 28 wt. % to about 75 wt. % hexafluoroacetone (HFA) and fromabout 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I), from about45 wt. % to about 70 wt. % hexafluoroacetone (HFA) and from about 30 wt.% to about 55 wt. % trifluoroiodomethane (CF₃I), from about 59 wt. % toabout 60 wt. % hexafluoroacetone (HFA) and from about 40 wt. % to about41 wt. % trifluoroiodomethane (CF₃I), or about 59.78 wt. %hexafluoroacetone (HFA), and about 40.22 wt. % trifluoroiodomethane(CF₃I). The azeotrope or azeotrope-like composition may consistessentially of hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I)in the above amounts, or consist of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) in the above amounts.

The azeotrope or azeotrope-like composition of the present disclosurehas a boiling point of about −29.84° C.±0.30° C. at a pressure of about14.40 psia±0.30 psia.

Stated alternatively, the azeotrope or azeotrope-like compositioncomprises, consists essentially of, or consists of, as little as about28 wt. %, about 45 wt. % or about 59 wt. %, or as great as about 60 wt.%, about 70 wt. % or about 75 wt. % hexafluoroacetone (HFA), or withinany range defined between any two of the foregoing values, and theazeotrope or azeotrope-like composition comprises, consists essentiallyof, or consists of, as little as about 25 wt. %, about 30 wt. % or about40 wt. %, or as great as about 41 wt. %, about 55 wt. % or about 72 wt.% trifluoroiodomethane (CF₃I), or within any range defined between anytwo of the foregoing values. In one embodiment, the azeotrope orazeotrope-like composition comprises, consists essentially of, orconsists of, about 59.78 wt. % and hexafluoroacetone (HFA) and about40.22 wt. % of trifluoroiodomethane (CF₃I). The azeotrope orazeotrope-like composition of the present disclosure has a boiling pointof about −29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30psia.

The present disclosure also provides a composition comprising theazeotrope or azeotrope-like composition. For example, there is provideda composition comprising at least about 5 wt. % of the azeotrope orazeotrope-like composition, or at least about 15 wt. % of the azeotropeor azeotrope-like composition, or at least about 50 wt. % of theazeotrope or azeotrope-like composition, or at least about 70 wt. % ofthe azeotrope or azeotrope-like composition, or at least about 90 wt. %of the azeotrope or azeotrope-like composition.

The azeotrope or azeotrope-like composition comprising, consistingessentially of, or consisting of effective amounts of hexafluoroacetone(HFA) and trifluoroiodomethane (CF₃I) disclosed herein may be used forseparating impurities from hexafluoroacetone (HFA) and/ortrifluoroiodomethane (CF₃I). One impurity that may be present intrifluoroiodomethane (CF₃I) is trifluoromethane (HFC-23).

The preparation of azeotropic or azeotrope-like compositions comprising,consisting essentially of, or consisting of effective amounts ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) allowsseparation techniques such as azeotropic distillation, for example, tobe used to remove impurities from trifluoroiodomethane (CF₃I) to providetrifluoroiodomethane (CF₃I) of high purity.

In one example, an azeotrope or azeotrope-like composition comprising,consisting essentially of, or consisting of effective amounts ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) may be formedfrom a composition including one or both of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) together with one or more other chemicalcompounds other than hexafluoroacetone (HFA) and trifluoroiodomethane(CF₃I), such as impurities. Following the formation of the azeotrope orazeotrope-like composition, the azeotrope or azeotrope-like compositionmay be separated from the other chemical compounds by a suitable method,such as by distillation, phase separation, or fractionation.

In this manner, the present disclosure provides a method of separatinghexafluoroacetone (HFA) as an impurity from a primary, crude compositionof trifluoroiodomethane (CF₃I) which includes hexafluoroacetone (HFA) asan impurity together with at least one additional impurity, includingthe steps of providing a primary composition of crudetrifluoroiodomethane (CF₃I), hexafluoroacetone (HFA) as an impurity, andat least one additional impurity, and subjecting the primary compositionto distillation, for example, at conditions effective to form asecondary composition which is an azeotrope or azeotrope-likecomposition comprising, consisting essentially of, or consisting ofeffective amounts of hexafluoroacetone (HFA) and trifluoroiodomethane(CF₃I), and separating the secondary composition from the primarycomposition by a separation technique such as phase separation,distillation, or fractionation, for example. Thereafter, the primarycomposition may be subjected to further separation or purification stepsto obtain purified trifluoroiodomethane (CF₃I).

The following non-limiting Examples serve to illustrate the disclosure.

EXAMPLES Example 1—Ebulliometer Study

An ebulliometer was used to measure azeotrope and azeotrope-likecompositions of hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I).The ebulliometer included a vacuum jacketed glass vessel which wassealed at the bottom and open to the atmosphere at the top. The top, orcondenser jacket, of the ebulliometer was filled with a mixture of dryice and ethanol to attain a temperature of about −72° C., which issignificantly lower than the normal boiling points of −27.76° C. forhexafluoroacetone (HFA) and −22.29° C. for trifluoroiodomethane (CF₃I)at a pressure of 14.40 psia. In this manner, it was ensured that allvapors in the system were condensed and flowed back into theebulliometer such that the liquid and vapor phases were in equilibrium.A quartz-platinum thermometer with an accuracy of ±0.002° C. wasinserted inside the glass vessel and used to determine the temperatureof the condensed vapor corresponding to the equilibrium boiling point ofthe mixture. Boiling chips were used to assist with maintaining a smoothboiling of the mixture in the ebulliometer.

The following procedure was used.

1. The quartz thermometer was immersed into a long dewar which containedan ice/water slurry and it was verified that the thermometer read 0° C.The dewar was deep enough so that at least ¾ the length of thethermometer shaft was immersed in the ice/water. The thermometerresistance was recorded in ohms.

2. The condenser jacket was loaded to ¼ full with ethanol. The condenserjacket was cooled by slowly introducing dry ice to avoid boiling overand/or splashing of the ethanol.

3. A known amount of trifluoroiodomethane (CF₃I) or hexafluoroacetonewas added to the ebulliometer and brought to a vigorously refluxingcondition. The temperature and atmospheric pressure were recorded usinga barometer with a temperature indicator.

The measurement was carried out in two steps. In a first step, about16.30 g of hexafluoroacetone (HFA) having a purity of 99 area %(synquest lot 418700) as determined by gas chromatography (GC) was firstintroduced to the ebulliometer by weighing the container before andafter the addition using a balance having an accuracy of ±0.01 g. Theliquid was brought to a boil and the equilibrium temperature of thehexafluoroacetone (HFA) was recorded at the recorded barometricpressure. Then, trifluoroiodomethane (CF₃I) having a purity of 99.99area % as determined by gas chromatography (GC) was introduced in smallincrements into the ebulliometer and the equilibrium temperature of thecondensed liquid mixture was recorded.

In a second step, about 22.76 g of trifluoroiodomethane (CF₃I) having apurity of 99.99 area % as determined by gas chromatography (GC) wasintroduced to the ebulliometer by weighing the container before andafter the addition using a balance having an accuracy of ±0.01 g. Theliquid was brought to a boil and the equilibrium temperature of thetrifluoroiodomethane (CF₃I) was recorded at the recorded barometricpressure. Then, hexafluoroacetone (HFA) having a purity of 99 area %(synquest lot 418700) as determined by gas chromatography (GC) wasintroduced in small increments into the ebulliometer and the equilibriumtemperature of the condensed liquid mixture was recorded

Data from the above first and second steps was combined to complete thecomposition range data from 0 to 100 weight percent of each of thehexafluoroacetone (HFA) and the trifluoroiodomethane (CF₃I) presentedbelow in Table 1, which shows a minimum in temperature which indicatesthat an azeotrope had been formed, and this data is also presented ingraphic form in FIG. 1. The bubble point temperature of the mixtureremained constant indicating that the mixture was azeotrope-like over alarge composition range.

TABLE 1 Ebulliometer Study of CF₃I/ hexafluoroacetone at P = 14.40 psiaT (° C.) wt. % Hexafluoroacetone wt. % CF₃I (+/− 0.01° C.) (+/− 0.1)(+/− 0.1) −27.76 100.00 0.00 −27.96 98.37 1.63 −28.37 94.72 5.28 −28.7290.82 9.18 −29.09 85.68 14.32 −29.41 80.01 19.99 −29.63 74.84 25.16−29.74 71.06 28.94 −29.78 67.09 32.91 −29.81 64.29 35.71 −29.84 60.9839.02 −29.84 58.59 41.41 −29.83 55.96 44.04 −29.81 53.35 46.65 −29.7949.83 50.17 −29.86 45.58 54.42 −29.80 41.7 58.22 −29.73 35.65 64.35−29.57 27.86 72.14 −29.42 21.35 78.65 −29.21 14.79 85.21 −27.21 5.7294.28 −23.68 1.68 98.32 −22.29 0.00 100.00

Example 2—Separation of Impurities

In this Example, a crude composition of trifluoroiodomethane (CF₃I) isprovided, including hexafluoroacetone (HFA) as an impurity, along withother impurities such as trifluoromethane (HFC-23). This composition isthen subjected to distillation at conditions effective to form andseparate an azeotrope or azeotrope-like composition of hexafluoroacetone(HFA) and trifluoroiodomethane (CF₃I) from the remainder of thecomposition. The separated azeotrope or azeotrope-like composition ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) is removed fromthe remaining crude composition of trifluoroiodomethane (CF₃I) as alight component. The remaining crude composition of trifluoroiodomethane(CF₃I) is then subjected to different temperature and pressureconditions wherein the other impurities such as trifluoromethane(HFC-23) may be separated by further distillation to obtain purifiedtrifluoroiodomethane (CF₃I).

Aspects

Aspect 1 is an azeotrope or azeotrope-like composition comprisingeffective amounts of hexafluoroacetone (HFA) and trifluoroiodomethane(CF₃I).

Aspect 2 is the azeotrope or azeotrope-like composition of Aspect 1,comprising from about 28 wt. % to about 75 wt. % hexafluoroacetone (HFA)and from about 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I).

Aspect 3 is the azeotrope or azeotrope-like composition of Aspect 2,comprising from about 45 wt. % to about 70 wt. % hexafluoroacetone (HFA)and from about 30 wt. % to about 55 wt. % trifluoroiodomethane (CF₃I).

Aspect 4 is the azeotrope or azeotrope-like composition of Aspect 3,comprising from about 59 wt. % to about 60 wt. % hexafluoroacetone (HFA)and from about 40 wt. % to about 41 wt. % trifluoroiodomethane (CF₃I).

Aspect 5 is the azeotrope or azeotrope-like composition of Aspect 4,comprising about 59.78 wt. % hexafluoroacetone (HFA) and about 40.22 wt.% trifluoroiodomethane (CF₃I).

Aspect 6 is the azeotrope or azeotrope-like composition of any ofAspects 1 to 5, wherein the composition has a boiling point of about−29.84° C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.

Aspect 7 is the azeotrope or azeotrope-like composition of any ofAspects 1 to 6, consisting essentially of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I).

Aspect 8 is the azeotrope or azeotrope-like composition of any ofAspects 1 to 7, consisting of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I).

Aspect 9 is a composition comprising the azeotrope or azeotrope-likecomposition of any of Aspects 1 to 8.

Aspect 10 is the composition of Aspect 9, comprising at least about 5wt. % of the azeotrope or azeotrope-like composition.

Aspect 11 is the composition of Aspect 10, comprising at least about 15wt. % of the azeotrope or azeotrope-like composition.

Aspect 12 is the composition of Aspect 11, comprising at least about 50wt. % of the azeotrope or azeotrope-like composition.

Aspect 13 is the composition of Aspect 12, comprising at least about 70wt. % of the azeotrope or azeotrope-like composition.

Aspect 14 is the composition of Aspect 13, comprising at least about 90wt. % of the azeotrope or azeotrope-like composition.

Aspect 15 is a method of forming an azeotrope or azeotrope-likecomposition comprising the step of combining hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) to form the azeotrope or azeotrope-likecomposition comprising effective amounts of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I).

Aspect 16 is the method of Aspect 15, the method comprising the step ofcombining hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) toform the azeotrope or azeotrope-like composition of any of Aspects 1 to8.

Aspect 17 is a method of separating hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) from a primary composition comprisinghexafluoroacetone (HFA), trifluoroiodomethane (CF₃I) and at least oneimpurity, including the steps of forming, within the primarycomposition, a secondary composition which is an azeotrope ofazeotrope-like composition comprising effective amounts ofhexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I); and separatingthe secondary composition from the primary composition and the at leastone impurity.

Aspect 18 is the method of Aspect 17, wherein the azeotrope orazeotrope-like composition is as defined in any of Aspects 1 to 8.

Aspect 19 is the method of Aspect 17 or 18, in which the separation iscarried out by at least one of phase separation, distillation, andfractionation.

As used herein, the phrase “within any range defined between any two ofthe foregoing values” literally means that any range may be selectedfrom any two of the values listed prior to such phrase regardless ofwhether the values are in the lower part of the listing or in the higherpart of the listing. For example, a pair of values may be selected fromtwo lower values, two higher values, or a lower value and a highervalue.

As used herein, the singular forms “a”, “an” and “the” include pluralunless the context clearly dictates otherwise. Moreover, when an amount,concentration, or other value or parameter is given as either a range,preferred range, or a list of upper preferable values and lowerpreferable values, this is to be understood as specifically disclosingall ranges formed from any pair of any upper range limit or preferredvalue and any lower range limit or preferred value, regardless ofwhether ranges are separately disclosed. Where a range of numericalvalues is recited herein, unless otherwise stated, the range is intendedto include the endpoints thereof, and all integers and fractions withinthe range. It is not intended that the scope of the disclosure belimited to the specific values recited when defining a range.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variancesthat fall within the scope of the appended claims.

What is claimed is:
 1. A composition comprising an azeotrope orazeotrope-like composition consisting essentially of effective amountsof hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I).
 2. Thecomposition of claim 1, wherein the azeotrope or azeotrope-likecomposition has a boiling point of about −29.84° C.±0.30° C. at apressure of about 14.40 psia±0.30 psia.
 3. The composition of claim 1,wherein the azeotrope of azeotrope-like composition consists essentiallyof from about 28 wt. % to about 75 wt. % hexafluoroacetone (HFA) andfrom about 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I). 4.The composition of claim 1, wherein the azeotrope or azeotrope-likecomposition consists essentially of from about 45 wt. % to about 70 wt.% hexafluoroacetone (HFA) and from about 30 wt. % to about 55 wt. %trifluoroiodomethane (CF₃I).
 5. The composition of claim 1, wherein theazeotrope or azeotrope-like composition consists essentially of fromabout 59 wt. % to about 60 wt. % hexafluoroacetone (HFA) and from about40 wt. % to about 41 wt. % trifluoroiodomethane (CF₃I).
 6. Thecomposition of claim 1, wherein the azeotrope or azeotrope-likecomposition consists essentially of about 59.78 wt. % hexafluoroacetone(HFA) and about 40.22 wt. % trifluoroiodomethane (CF₃I).
 7. Acomposition comprising an azeotrope or azeotrope-like compositionconsisting essentially of hexafluoroacetone (HFA) andtrifluoroiodomethane (CF₃I) and having a boiling point of about −29.84°C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia.
 8. Thecomposition of claim 7, wherein the azeotrope or azeotrope-likecomposition consists essentially of from about 28 wt. % to about 75 wt.% hexafluoroacetone (HFA) and from about 25 wt. % to about 72 wt. %trifluoroiodomethane (CF₃I).
 9. The composition of claim 7, wherein theazeotrope or azeotrope-like composition consists essentially of fromabout 45 wt. % to about 70 wt. % hexafluoroacetone (HFA) and from about30 wt. % to about 55 wt. % trifluoroiodomethane (CF₃I).
 10. Thecomposition of claim 7, wherein the azeotrope or azeotrope-likecomposition consists essentially of from about 59 wt. %hexafluoroacetone (HFA) to about 60 wt. % hexafluoroacetone and fromabout 40 wt. % trifluoroiodomethane (CF₃I) to about 41 wt %trifluoroiodomethane (CF₃I).
 11. The composition of claim 7, wherein theazeotrope or azeotrope-like composition consists essentially of about59.78 wt. % hexafluoroacetone (HFA) and about 40.22 wt. %trifluoroiodomethane (CF₃I).
 12. The composition of claim 7, wherein theazeotrope or azeotrope-like composition consists of from about 28 wt. %to about 75 wt. % hexafluoroacetone (HFA) and from about 25 wt. % toabout 72 wt. % trifluoroiodomethane (CF₃I).
 13. The composition of claim7, wherein the azeotrope or azeotrope-like composition consists of fromabout 45 wt. % to about 70 wt. % hexafluoroacetone (HFA) and from about30 wt. % to about 55 wt. % trifluoroiodomethane (CF₃I).
 14. Thecomposition of claim 7, wherein the azeotrope or azeotrope-likecomposition consists of about 59.78 wt. % hexafluoroacetone (HFA) andabout 40.22 wt. % trifluoroiodomethane (CF₃I).
 15. A method of formingan azeotrope or azeotrope-like composition comprising the step ofcombining hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) toform an azeotrope or azeotrope-like composition consisting essentiallyof hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) having aboiling point of about −29.84° C.±0.30° C. at a pressure of about 14.40psia±0.30 psia.
 16. The method of claim 15, wherein the combining stepcomprises combining from about 28 wt. % to about 75 wt. %hexafluoroacetone (HFA) and from about 25 wt. % to about 72 wt. %trifluoroiodomethane (CF₃I).
 17. The method of claim 15, wherein thecombining step comprises combining from about 45 wt. % to about 70 wt. %hexafluoroacetone (HFA) and from about 30 wt. % to about 55 wt. %trifluoroiodomethane (CF₃I).
 18. The method of claim 15, wherein thecombining step comprises combining about 59.78 wt. % hexafluoroacetone(HFA) and about 40.22 wt. % trifluoroiodomethane (CF₃I).
 19. A method ofseparating hexafluoroacetone (HFA) and trifluoroiodomethane (CF₃I) froma primary composition comprising hexafluoroacetone (HFA),trifluoroiodomethane (CF₃I) and at least one impurity, including thesteps of: forming, within the primary composition, a secondarycomposition which is an azeotrope or azeotrope-like compositionconsisting essentially of effective amounts of hexafluoroacetone (HFA)and trifluoroiodomethane (CF₃I) having a boiling point of about −29.84°C.±0.30° C. at a pressure of about 14.40 psia±0.30 psia; and separatingthe secondary composition from the primary composition at least oneimpurity.
 20. The method of claim 19, wherein the forming step comprisesforming, within the primary composition, a secondary composition whichis an azeotrope or azeotrope-like composition consisting essentially offrom about 28 wt. % to about 75 wt. % hexafluoroacetone (HFA) and fromabout 25 wt. % to about 72 wt. % trifluoroiodomethane (CF₃I) and havinga boiling point of about −29.84° C.±0.30° C. at a pressure of about14.40 psia±0.30 psia.